Superconducting wire materials have ceramics materials of superconducting layers, etc., and multi-layered thin film structures of metal layers.
FIG. 1 is an exemplary view illustrating a superconducting wire material based on Rolling Assisted Bi-axially Textured Substrate (RABiTS). Referring to FIG. 1, the superconducting wire material includes a buffer layer 14, a superconducting layer 16 and a stabilization layer 18 sequentially formed on a Ni or Ni alloy substrate 12.
A high-temperature superconducting wire material based on RABITS is thin and has ductility. Thus, in order to provide rigidity, a metal substrate 20 such as stainless steel, etc., is laminated on and below the superconducting wire material. In this case, the laminated substrate is combined by a solder 30 to have a high mechanical strength and is effective in reducing magnet property degradation generated during coil winding. However, there is a problem that the metal is laminated on both surfaces of the substrate, and thereby the entire wire material becomes thicker and current density Je becomes lower.
Meanwhile, a superconducting wire material based on Ion Beam Assistes Deposition (IBAD) forms a superconducting layer on a Hastelloy-based metal substrate with a relatively high strength. Even in this case, when a lamination substrate is used on both sides of the wire material, the wire material would have high rigidity which makes coil winding difficult, and would have a mechanical strength more than is required. Accordingly, current density would become lower.